The invention relates to a combination comprised of an intramedullary nail and a targeting and/or nailing instrument. More particularly, it relates to a coupling system for quickly connecting an instrument to a bone nail.
Intramedullary nails are generally driven into the intramedullary space using a so-called nailing instrument. The nailing instrument is connected using a suitable connection with the nail before the nail is driven into the bone with the aid of a hammer or the like. In the case of so-called locking nails, which are provided with transverse bore holes for receiving bone or locking screws, a targeting instrument serves also as the nailing instrument. The targeting instrument is connected with the facing end of the bone nail using a clip and a targeting section running parallel to the bone is used for locating the otherwise invisible transverse bore holes of the nail in the bone. For this reason, it is necessary to orient the nail and the targeting device in a predefined rotational position relative to each other. To this end, it is well-known to provide an axially parallel projection at the connection end of the targeting device, which engages in an axially parallel recess. The connection of the connection end of the targeting device with the nail is generally done with the aid of a screw or by using a screw sleeve as disclosed in U.S. Pat. No. 5,176,681. The screw sleeve is used to keep a passage open to the inside of the nail, so that it is possible to introduce or to actuate a locking screw in the nail, while the targeting device is connected with the nail. The locking screw is used to lock a femoral neck screw, which is passed through an inclined transverse bore hole of the nail. The locking screw prevents movement of the neck screw in particular in the direction of rotation, but allows axial movement of the neck screw.
The known system requires setting the nail on the targeting unit manually and at the same time screwing the parts together which is relatively cumbersome for one person acting alone.